Suspended ceiling systems are extensively used throughout the construction industry, both in new building construction and in the renovation of older buildings. A suspended ceiling consists of a grid-like support base suspended from the overhead structure, the base supporting a layer of ceiling panels. In addition, the suspended grid frequently serves as a support base for lighting fixtures and heating and air conditioning outlets, fire sprinklers, sensors, detectors, monitors, enunciators, speakers, and other such items. Ceiling space constraints often create difficult choices in controlled environment facilities because of competition for the optimum air outlet locations. Whenever hoods or containment devices are lined up at the room perimeter, the best air outlet locations are in the center, which is often where the benchtops and lighting are needed. The competition for space with lighting and other ceiling devices may lead to imperfect air outlet locations and potentially undesirable large scale airflow patterns (eddies). Many times the dynamic controls for the room HVAC (heating, ventilating and air-conditioning) system contributes to variable large scale airflow eddies which decrease the containment efficiency of hoods and other exhausted devices. These eddies create cross drafts that impair proper hood functioning. Usually, cross drafts require hood performance enhancements through increased exhaust and supply air flow rates, which lead to increases in energy costs. The design engineers must address all of these concerns, but the equipment available today does not lead to easy solutions. Once these considerations are addressed in high tech facilities, much of the ceiling tiles are no longer removable because of the devices rigidly mounted in them. This leads to difficult compromises that impair above ceiling access and facility maintenance operations.
There have been several past combination lighting and HVAC fixtures, but most applications have been intended for ceiling mounted clean room filtration. These inventions do not address the safety issues of hazardous compound containment devices (hoods and other exhausted cabinets) by promoting uniform room scale airflow patterns and minimizing cross drafts. In addition, the energy efficiency of the lighting and airflow control has not been combined in other products currently available. A fixture with a design focused on recyclability and is made from mostly recycled materials is not available today, but is needed in Green Building applications.